


A TECHNICAL DESCRIPTION 



OF THE 



ENGINEERING BUILDING 



OF THE 



INSTITUTE OF TECHNOLOGY. 




THE ENGINEERING BUILDING. 



PROCEEDINGS OF THE SOCIETY OF ARTS. 
Massachusetts Institute of Tecliuology. 



A TECHNICAL DESCRIPTION 



OF THE 



ENGINEERING BUILDING 



OF THE 



INSTITUTE OF TECHNOLOGY. 



BOSTON : 
W. J. ScHOFiELD, Printer, 105 Summer Street, 

1890. 




i\^}^*^,., 



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A Technical Description of the Engineering Building 
of the Institute of Technology. 



By Profs. F. W. Chandler (Architecture) ; G. Lanza (Mechanical Engineer- 
ing) ; G. F. Swain (Civil Engineering) ; and Mr, S. H. Woodbridge 
(Heating and Ventilating). 



At a meeting of the Societ}' of Arts held in the Engineering 
Building, Thursday, May 8, 1890, the New Engineering Building was 
described as follows : 

Prof. .Chandler said : The Engineering Building of the Insti- 
tute of Technology is built on Trinity Place, a short distance from 
the other buildinors of the Institute. The structure measures 148 feet 
by 52 feet, and has six stories. Its height of 85 feet is the extreme 
limit allowed by the building laws when a wooden construction is used. 
Its position on the lot was very carefully considered in regard to 
future additions to the south on the property of the Institute ; and, by 
mutual agreement with the abutters, there will always be a clear area 
of 30 feet to the north. 

The scheme of the building is what is known as modern mill con- 
struction. A row of cast iron columns, placed eight feet from center 
to center, runs lengthwise of the building, giving spans of twenty-four 
feet from column to wall. The strength of the brick wall is concen- 
trated in buttresses opposite the columns, and thinner walls unite them, 
and because these thinner walls are not necessary for the stability of 
the building, the greater part of this space is occupied by windows, 
the heads of which extending between the beams, as there are no 
ceilings, to the underfloor give that high light which is the most 
effective in lighting a large room. A pair of southern pine beams 
extends from each column to each side wall. These doubled beams 



are in all cases bolted together with eight f-inch iron bolts to each 
pair, leaving a space of one inch between for ventilation, kept open by 
iron washers. The beams are framed to fit snugly around the columns, 
and the ends of the abutting timbers are fastened together by dogs of 
f-inch iron, the ends of which are turned down and driven into holes 
in the beams. These timbers are also fastened at the under side by 
lag screws through the caps of the columns. The other ends rest on 
cast-iron plates one inch thick, and are carried into the wall eight 
inches, and one inch of air space is left about the ends for ventilation. 
To tie these beams to the walls a one-inch bolt is put through each 
pair of beams eight inches from the wall, and at the same time through 
the eye of another one-inch bolt which lies between the timbers, the 
nut end being on the outside of the building, and pressing against a 
cast-iron washer. Across these paired beams are carried plank under- 
floors of spruce, four inches thick in the basement and three inches 
thick elsewhere. These planks are laid with splines. The upper 
floors throughout are of maple and |- inches thick. Between the 
lower and upper floors, in addition to the asbestos paper required by 
law, are three thicknesses of heavy deadening felt, and two of tarred 
paper. 

The construction of the roof is like that of the floors. 

It does not yet appear by whom the slow-burning construction, 
as applied to mills, has been evolved, or when was first made use of 
heavy timbers set wide apart carrying a solid floor. But for a long 
time after these floors were in use, even in Lowell, the roofs were 
bad either in form or structure until Mr. William B. Whiting, the 
Vice-President of the Boston Manufacturers Fire Insurance Co., sug- 
gested the adoption of what is called the deck roof, constructed like 
the floors, and the Engineering Building is a development of the 
Mutual Underwriters more than anyone else. 

The structure throughout is of unusual strength, for the aim was 
to have a building which should be sufficiently free from vibration 
when the heavy machinery was running in the basement, to admit of 
experiments being made there, requiring delicate measurements, and 
because the four upper floors were to be chiefly used for draughting 
rooms. The iron columns decrease in size from the one in the base- 
ment measuring 11^ inches in diameter with a l^inch shell to the one 
in the sixth story, 6 inches in diameter with an inch shell. These 



columns resting on each other have their ends carefully turned in a 
lathe to ensure perfectly accurate bearings,— the head of one column 
having a seat countersunk ^ inch to receive the foot of the next column. 
In the mill proper these columns are of wood, but, on account of the 
great weight to be carried in this structure, much valuable space could 
be saved by using iron. 

The beams of the basement floor measure each 11 inches by 18, 
those of the first floor 10 inches by 18, those of the second 7 inches 
by 16, and those above 6 inches by 16, and those of the roof 6 inches 
by 14. 

There are no boilers in this building, the steam for heating and 
for power is brought from the boilers in the basement of the Rogers 
Building, about a thousand feet away, through a six-inch pipe buried 
under ground. The pipe is first wrapped in asbestos, and for further 
insulation it is inserted in a wooden log. 

The heating system is partly direct and partly indirect, and with 
the indirect part ventilation is obtained by means of a Sturtevant 
blower. Nearly all the radiators have automatic valves, the tempera- 
ture of the room regulating the steam supply to the radiator. 

In connection with the heating should be mentioned that the 
window sashes of the north, east, and west sides of the building, and 
also a large skylight on the roof measuring 80 by 16 feet, lighting the 
upper draughting room, are double glazed, making a great saving in 
the expenditure of heat. 

The exterior design is very simple, all effect being obtained by 
the principle of construction. The solid basement from which rises 
the long buttresses or pilasters, connected at the top by semi-circular 
arches, and the upper story with its thinner wall forming an attic, 
describes the design. And it is effective enough ; it tells its story 
truly. The material is rough brick with a small amount of Long 
Meadow stone trimmings. 

A heavy block granite foundation rests on 725 piles, averaging 
40 feet long. All the heavy machinery in the basement have their 
piled foundations distinct from that of the building. 

There can hardly be a more fire-proof structure. First, its isola- 
tion ; then there is not a concealed space anywhere, no furrings on 
the walls, — the brick is the only finish, no ceilings, with their dangerous 
air spaces the depth of the floor joists, — the staircase is built open in 



6 

the same way, — the ventilation and heating ducts running from the 
basement out through the roof are of iron. Water is on every floor, 
and the standpipe is carried to the roof. An iron staircase, built in a 
brick tower, runs to the roof to serve as fire escape. 

The building is occupied by the Mechanical Engineering and 
Civil Engineering Departments. The two lower stories are the labora- 
tories of the Mechanical Engineering Department, and this department 
also has the two middle floors, which are devoted to drafting and reci- 
tation rooms. The two upper stories contain similar rooms for the 
Civil Engineering Department, and the library common to both 
departments. 

The Laboratories. 

Prof. Lanza was next introduced to describe the laboratories. 

Pi^of.^LANZA said : These laboratories are now called the Engi- 
neering Laboratories, and the building is called the Engineering 
Building, because it is especially devoted to the engineering work of 
the school, both the general and the special. Thus, in its recitation 
rooms are taught the classes in mechanism, in thermo-dynamics and 
steam engineering, in hydraulics, and in strength of materials, all of 
which may be called general engineering studies, as all these subjects 
are taught, to a greater or less extent, to the students of civil, of 
mechanical, of mining, of chemical, and of electrical engineering. 
Besides this, all the drawing-room work of the students of these 
courses is done in this building, and all the purely professional work 
of the civil and mechanical engineering courses is carried on here ; 
this including practically all the engineering work proper of the above 
stated courses. Hence it follows that it is the building where the 
purely engineering work is done for all departments of the school. 

The Laboratories are really an aggregation of the following : — 

1. A laboratory devoted to experimental work upon the strength 
and other resisting properties of materials used in construction. 

2. A laboratory of steam engineering. 

3. An hydraulic laboratory. 

4. A laboratory where other engineering experiments are made, 
but which is not yet sufficiently differentiated to be divided into its 
component parts. 

The objects to be accomplished by these laboratories are the 
following: — 



First. To give the students practice in such experimental work 
as any engineer is constantly liable to be called upon to perform in 
the practice of his profession, — as boiler tests, engine tests, power 
determinations, etc. 

Second. To give the students some experience in carrying ou 
original investigations in engineering subjects with such care and accu- 
racy as to render the results of real value to the engineering community. 

Third. By publishing from time to time the results of such 
investigations, to add gradually to the common stock of knowledge. 

The two lower floors of the building are entirely devoted to the 
Engineering Laboratories, thus increasing their capacity from about 
5,550 square feet, as in the Rogers Building, to about 13,900 square 
feet. Cuts of these laboratories are shown here, and the following 
statement of the apparatus they contain is copied from the twenty-fifth 
Catalogue of the Institute : — 

" The laboratory for testing the strength of materials is furnished 
with the following apparatus. An Olsen testing machine of 50,000 
pounds' capacity, for determining tensile strength, elasticity, and com- 
pressive strength. A testing machine of the same capacity for deter- 
mining the transverse strength and stiffness of beams up to 25 feet in 
length, and the framing-joints used in practice. Machinery for the 
measurement of the strength, twist, and deflection of shafting while 
running and under the conditions of practice. Machines for time tests 
of the transverse strength and deflection of full-sized beams ; for test- 
ing the tensile strength of mortars and cements, and of ropes ; for 
testing the effect of repeated stresses upon the elasticity and strength 
of iron and steel ; for determining the strength and elasticity of wire ; 
for determining the deflection of parallel rods when running under 
different conditions. Also, accessory apparatus for measuring stretch, 
deflection, and twist. 

" The steam laboratory contains, — a triple expansion engine, with 
cylinders of 9 inches, 16 inches, and 24 inches diameter respectively, 
and 30 inches stroke, arranged in such a way as to be run single, 
compound, or triple, as desired for the purposes of experiment. This 
engine is of the Corliss type, and was built by E. P. AUis & Co. It 
will have a capacity of about 150 horse-power when running triple, 
with an initial pressure of 150 pounds in the high-pressure cylinder. 
It is connected with a surface condenser and all the other apparatus 
necessary to adapt it to the purposes of accurate experiment. 



8 

" This laboratory also contains a 16 horse-power Harris-Corliss 
engine, and an 8 horse-power engine, used for giving instruction in 
valve-setting, etc. It is also equipped with several surface condensers, 
steara pumps, calorimeters, mercurial pressure and vacuum columns ; 
apparatus for determining the quantity of steam issuing from a given 
orifice or through a short tube under a given difference of pressure ; 
apparatus for testing injectors ; and with indicators, planimeters, 
gauges, thermometers, anemometers, and other accessory apparatus. 

*' The engineering laboratories are also provided with a number of 
friction brakes ; with machinery for determining the tension required 
in a belt or rope to enable it to carry a given power at a given speed, 
with no more than a given amount of slip ; with three transmission 
dynamometers ; with a complete set of Westinghouse air-brake appa- 
ratus, including the parts belonging on the car and on the locomotive ; 
with cotton machinery as follows, namely, two cards, a drawing frame, 
a speeder, a fly frame, a ring frame, and a mule, as well as accessory 
apparatus. There are also available for the purposes of experiment, 
in connection with the work of these laboratoties, two horizontal tubu- 
lar boilers, one large Babcock and Wilcox boiler, and a Porter- Allen 
engine of about 80 horse-power, all situated in the Rogers Building ; 
also another boiler, a 40 horse-power Brown engine, a number of 
looms, and other apparatus in the workshops on Garrison Street." 

The most important addition to the equipment of these labora- 
tories is that of the triple-expansion engine, inasmuch as it is the first 
triple-expansion engine of a practical size that has ever been arranged 
for making experiments ; and by its means the laboratories are placed 
in a position which will enable them to do work for the triple engine 
of a character similar to that done for the compound engine by the 
United States Naval Engineers in 1874, and also to make such 
researches with a triple or a compound engine as were made upon 
single engines by Hirn, Hallauer, and others. 

The laboratory with its present equipment furnishes the means, 
— 1st, of accommodating the number of students that now need this 
instruction, with an opportunity for some growth ; 2nd, of giving good 
laboratory instruction to the students ; 3rd, of carrying on investiga- 
tions of importance in the engineering line. All this can be done, 
inasmuch as the building is adapted to the purposes of an engineering 
laboratory, — a fact which was never true of the Rogers Building. 




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The Hydraulic Laboratory. 

At the close of Prof. Lanza's remarks, Prof. G. F. Swain was 
introduced, who described the Hydraulic Laboratory. 

Prof. Swain said: The erection of the new engineering building 
of the Institute of Technology, to be occupied by the departments of 
Civil and Mechanical Engineering, offered an opportunity for a con- 
siderable extension in the Engineering Laboratories, and an attempt 
has been made to improve this opportunity by laying the foundation 
for a laboratory for hydraulic experiments, which should be so arranged 
as to permit of the carrying out of any experiments in hydraulics 
which it is practicable to perform within walls. Hydraulic experiments 
on a large scale must necessarily be performed out of doors, since the 
measurement of large quantities of water requires apparatus and appli- 
ances which cannot be accommodated within walls. Thus, the weir 
experiments of Mr. Francis, at Lowell, were made by taking the water 
from one of the canals, and using a lock as a measuring basin ; those of 
Messrs. Fteley and Stearns, at South Framingham, were made by 
using a portion of the Sudbury River Aqueduct as a measuring basin ; 
the orifice experiments of General Ellis, at Holyoke, were made in 
connection with the fall between two levels of the canal at that place ; 
and the recent elaborate and careful experiments by Mr. Freeman on 
the flow of water through fire hose, the discharge of nozzles, and the 
height of jets, were made at Lawrence, where the hydrant system of 
one of the mills, as well as the city water supply, could be made 
use of. 

But while experiments such as these are clearly excluded from 
among those which can be made in connection with an hydraulic labo- 
ratory in an institution of learning, there remain a large number which 
can properly be conducted within doors with the aid of suitable ap- 
paratus, and which, though they may be on a small scale as regards 
the quantities of water employed, nevertheless offer a large field for 
scientific^ investigation. The new laboratory of the Institute, as 
already stated, has been planned with a view to affording opportunity, 
as the work is extended, for carrying on any experiments which are 
thus practicable ; that is to say, in the following directions : — 

1. Experiments on the flow through orifices of small size, both 
free and submerged, and either sharp-edged, rounded, or fitted with 



12 

inside or outside mouth-pieces of various kinds, and under heads rang- 
ing as high as above seventy feet. 

2. Experiments on the flow of water over weirs of small size, 
either free or submerged. 

3. Experiments on the loss of head in small pipes of various 
kinds. 

4. Experiments on the loss of head due to bends, curves, valves, 
diaphragms, or other obstructions causing sudden changes of velocity. 

5. Experiments on the distribution of velocity in different parts 
of a liquid cross-section, either of a jet from an orifice, of a sheet dis- 
charged over a weir, or of a liquid flowing in a pipe. 

6. Experiments on different water meters, including Mr. Her- 
schel's Venturi meter, as well as the ordinary forms in the market. 

7. The testing of small turbines and of various other small 
motors. 

8. Experiments on the pressure of jets against plane or curved 
surfaces, and on the resistance of standing water to the motion of 
surfaces of different shapes through it. 

9. Experiments on the siphonage of traps, and on other matters 
connected with plumbing arrangements of houses. 

The development of a laboratory which shall admit of experi- 
ments in all these lines must necessarily be slow and expensive, and 
the laboratory in the Institute, being only a few months old, is not 
yet fully equipped to carry on any of these experiments excepting 
those on the flow of water through orifices. It is believed, however, 
that the foundation has been laid for the rapid development of re- 
search in the remaining directions which have been enumerated, and 
the object of the present paper is briefly to describe and illustrate the 
apparatus thus far provided or proposed. 

In order to be able to work with large heads, and to be independ- 
ent of the city water supply, as well as to provide for the varied ex- 
periments enumerated, it was first necessary to erect a tank and 
standpipe. The tank is shown in Figure 1. It is made of " Shell " 
steel ^ inch in thickness, is 5 feet in diameter and about 28 feet high, 
resting on a concrete foundation and extending up through two floors. 
It consists of six courses of steel, with girth seams single riveted, and 
longitudinal seams double riveted, and with heads of j^^-inch steel 
dished, as shown in the figure. It is provided with orifices as fol- 
lows : — 



13 

In the lowest course, a man-hole 24 inches by 12 inches at M; 
at P, a flanged nozzle with elbow for connecting to 10-iuch standpipe, 
as shown in Figure l/>. 

In the second course, a 10-inch orifice at G, a second at F, a 
third at D, and a fourth at C. The orifice at F may be used, if de- 
sired, for connecting with a small turbine placed below the floor. 
That at G is for experiments on submerged orifices. Those at D and 
C are for experiments on free orifices, or for connecting lines of pipe 
with the tank. Enclosing the orifice at G, an angle-iron and two bent 
plates are attached to the side of the tank, as shown, to which a 
wooden tank extending horizontally and resting on the floor is to be 
attached. In this wooden tank will be placed a weir, and the water 
will flow through the submerged orifice at G, or through a submerged 
mouth-piece, either inside or outside, and either converging or diverg- 
ing, and will then flow over the measuring weir. The orifice C is 
fitted for experiments on free orifices, as will subsequently be de- 
scribed. The orifice D is to be fitted with a piece to which pipes can 
be attached as desired, thus enabling the losses of head at diaphragms, 
valves, curves, etc., to be studied. On the same level with the orifices 
D and G connections are made for mercury gauges. 

In the third course, a If-inch orifice at G" and another at C", 
nearly above the large orifices G and C. These small orifices are for 
the shafts of the hand-wheels for raising the gates over the large 
orifices, as will presently be explained. 

In the fifth course, orifices similar to those in the second course ; 
and in the sixth course, orifices similar to those in the third course ; 
thus rendering it possible to carry on experiments simultaneously 
upon two floors of the building. The top of the tank is provided with 
a flanged nozzle for connecting with the 10-inch standpipe, as shown 
in Figure 15. 

The size of the tank is such that, with the orifices which it will 
be practicable to use, the velocity in the tank will be so small that it 
may be neglected, and the disturbance due to the inflowing water from 
the standpipe will also be small. Nevertheless, two gratings have 
been arranged, one at the top and one at the bottom. These gratings 
consist of plates of -J-inch iron perforated by J-inch holes about an 
inch apart. They are made in three pieces, and rest upon angle-iron 
brackets riveted to the inside of the tank. The tank itself rests upon 
cast-iron supports, as shown in Figure 1. 



14 

The general arraDgement of the tank and standpipes is shown in 
Figures 15 to 18. Figure 15 shows the plan of the sub-basement, 
with the location of the tank, the rotary pump, and the steam pump. 
The tank a is connected, as shown, by the top connection e and the 
lower connection^ to the 10-inch wrought-iron standpipe J, which, as 
shown in Figure 17, extends to the top of the building, and is closed 
at the top. The connection y is tapped by the small pipe g, by means 
of which the water may be drawn out of the system into the cistern 
h. The pumps take water from this cistern h and deliver it into pipe 
h which, as shown in Figure 17, is arranged to carry it directly to 
the standpipe through the valve 5, or to the 3-inch pipe c through the 
valve t. For use in the hydraulic experiments, the valve s is closed 
and the valve t opened, the water being thus delivered into the 3-inch 
pipe c c. From this pipe the flow into the 10-inch pipe is regulated 
by the valves w, which enable the head in the 10-inch pipe to be main- 
tained at an almost perfectly constant level. Any excess of water 
overflows through the pipes m into the discharge pipe d. The pipe c 
therefore serves as a regulator of the head, and it has been found to 
fulfil its purpose admirably. Attached to the standpipe &, and running 
from floor to ceiling, in each story, is a glass gauge placed in front 
of a graduated scale reading to hundredths of a foot. These gauges 
are enclosed in wooden boxes, which may be opened on the front and 
on one side, and which are placed so as to receive light directly from 
adjacent windows. The water is taken by the pumps from the cistern 
h, passes through pipes k and c and through the valves n into the 
standpipe h, thence through the connection e or f, or both, into the 
tank, from which it is discharged through orifices, or in any other way 
desired, and the discharge measured. Measurements are made by 
weighing the quantity of water discharged in a given time, the water 
being returned to the cistern ^, and thus used over and over again. 

The same apparatus, by suitable arrangement of the valves, will 
be employed in making tests of the pumps. 

The city water pipe is connected with the standpipe system at x. 

The soil pipe dd is arranged with single and double Y's in a way 
which will allow the carrying out of all kinds of experiments on the 
siphonage of traps, as mentioned under head 9 on page 138. This 
pipe is arranged with an ordinary trap at the foot, as shown in Figure 
16, and it discharges into the cistern h, as shown in Figure 15. 



15 

The details of the arrangement for measurements with simple 
free orifices are shown in Figures 2 to 14. In experiments of this 
description it is of course essential that the orifice shall be placed in 
a plane surface. It was therefore necessary to arrange the apparatus 
so that the curvature of the tank itself should not affect the flow. 
For this purpose a composition casting a (Figs. 2 and 3) is drawn up 
to the tank by eight f-inch bolts, as shown in Figure 3, which are 
screwed into the hub of the casting. The greater part of the casting 
is only \ inch in thickness, with eight strengthening ribs, as shown in 
Figure 2. In this casting is placed a piece, c, which is held in position 
by a ring-nut, dd^ which can be screwed or unscrewed by a spanner. 
When it is desired to use large or long orifices the piece c will contain 
the orifice, and by having various pieces c, with orifices of different 
shapes and sizes, numerous experiments may be carried out. The 
composition casting a is thickened on one side to f inch, as shown in 
Figures 2 and 3, to allow of the insertion of a sliding piece by means 
of which the horizontal dimension of a rectangular orifice may be 
varied, keeping the vertical dimension constant. When small orifices 
are to be used, it is not desirable to have them cut in as large a piece 
as the piece c. This piece c, therefore, as shown in Figure 3, is 
arranged to take a second piece, o, held in place by a second ring-nut, 
d! . Small orifices are made in pieces like the one o, as shown in 
Figure 3, and are of different sizes and shapes. 

It is desirable that one orifice may be removed and another sub- 
stituted in its place without completely emptying the tank. For this 
purpose a gate is designed to slide on the back of the casting a, so 
that, when it is desired to remove one orifice, the gate may be lowered 
and the water thus shut off, and a new orifice substituted in place of 
the old one. The gate may then be raised and the experiments con- 
tinued. This gate and the fittings connected with it are shown in 
Figures 4 to 14. Figure 4 shows a view of the gate from the inside, 
Figures 5 and 6 horizontal cross-sections, and Figure 7 a vertical 
cross-section. The gate is of cast iron, ribbed as shown, and is ar- 
ranged to slide in guides bolted at the bottom to the casting «, and at 
the top to the tank. These guides are shown in Figures 8 to 11. In 
order that the gate may be raised without having to overcome the 
friction due to the pressure of the water over the entire surface of 
the gate, the rod r, by which the gate is raised, is attached to an 



16 

aogle-iron, L (Figs. 4 and 7). When the gate is to be raised from 
the position shown in Figure 7, the angle-iron L is first raised until 
it strikes against the rib above it. This raising of L opens the orifice 
c?, thus allowing water to pass through the gate, and equalizing the 
pressure on the two sides, except over the small ring forming the 
bearing surface, the friction due to the pressure on which is, there- 
fore, the only friction to be overcome. The discharge orifice may be 
meanwhile closed by a plug from the outside, if necessary. When 
the gate is lowered, its own weight carries it down until it reaches the 
stop 5. The rod is then forced down, closing the orifice d. Figures 
12 to 14 show the hand-wheel, shaft, and stuffing box, by means of 
which the gate is raised, and require little explanation. The rod 
shown in Figure 7 is in its upper part a rack running in the space r 
(Fig. 12). 

Only one further point calls for explanation regarding the ar- 
rangement of the gate and stuffing box, namely, the modifications 
necessary for the case of inside mouth-pieces. When such mouth- 
pieces are used, the gate as shown would of course be inapplicable, 
and a new seat must be provided for it, so that it will pass clear of 
the inside mouth-piece. It is intended to accomplish this by bolting 
on to the composition casting a (Fig. 2) a circular channel-shaped rib, 
and adding new guides for the gate, thus making its seat at any 
desired distance back of the inside face of the casting. At the same 
time, in Figure 12, the pinion will be removed from the position 
shown, and placed outside of the bearing, where the collar is shown 
in the figure, and the collar placed on the inside. A new guide for 
the rack will then be bolted on, as shown by the dotted lines. 

As the new engineering building has been occupied only since 
February, 1890, and the hydraulic apparatus is thus but a few months 
old, the only apparatus thus far in use* is that for measuring the flow 
through simple, free orifices, and for making tests of pumps. It is 
hoped, however, that the remaining apparatus will be provided in the 
near future. The tank and the stand pipe system already procured 
furnish the foundation, and upon them the other apparatus may 
readily be built up. Experiments upon meters and upon motors may 
also be carried out without difficulty ; and, in fact, the possible lines 
of research are so varied that it is hoped that the establishment of 
this laboratory may lead to many useful results, and that it may con- 
tribute in some measure to the advancement of hydraulic science. 



17 

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24 

Heating, Heat Regulating, and Ventilating. 

At the close of Prof. Swain's paper, Mr. S. H. Woodbridge was 
introduced, who described the System of Heating, Heat E-egulating, 
and Ventilating-. 

Mr. W()0'dbridge said : This building is without interior walls 
other than light partitions, and all available external wall space is 
demanded for piers and windows. Locations were allowed for eight 
vertical flues (F) Fig. 1, varying from 9 to 12 sq. ft. in cross-section, 
for the supply and discharge ventilation of the thirty and more rooms. 
The rooms were arranged by their intended users with only partial 
reference to the fixed location of flues, and connecting air ducts were 
disapproved as unsightly. The great value of the basement floor 
space imposed a limit of 10' x 12' on the area to be surrendered to 
ventilating purposes. The use of the concrete floor of the sub-base- 
ment for apparatus, above and about which the basement floor is 
removed, precluded the use of this space as a distributing air chamber, 
and compelled the building of a continuous duct about the perimeter 
of the sub-basement, with one cross duct beneath the fan and into 
which it discharges at A-A, Fig. 1. The main duct, except where 
engine beds encroach upon it, is 15 sq. ft. in cross-section. The cross 
duct has nearly twice that area. The control of the air quantities to 
be moved in one direction or another within these ducts is effected 
by movable deflectors, one under the fan, and one at each end of the 
cross duct, Fig. 1. 

The perimeter ducts have for three of their sides the foundation 
wall of the building, the sub-basement concrete floor, and- the wooden 
floor of the basement. The fourth side is of galvanized iron, secured 
by nailing to wooden strips set in the concrete and nailed to the wooden 
floor and beams. A free use of elastic cement was made in all joints 
between metal and wood, and of paint in all locked or other joints of 
the sheet metal, and provision made for a possible settling away of the 
concrete from the wooden floor. 

To clear the laboratory ceiling and the floor space of all possible 
obstructions and the unsightly appearance of piping, the steam mains 
and branches, traps, etc., are placed within the air conduits. All such 
steam pipes are carefully pitched and drained and covered. In spite 
of the latter precaution the temperature of the air in transit from the 
fan to the most remote flues is raised some 12°. 



25 

The eight vertical ducts are of necessity made to serve the dual 
purpose of supply and discharge. To adapt them to such purpose, a 
diaphragm is fixed in such way as to provide two channels having areas 
proportioned to the quantities of fresh and spent air to be moved 
through them to and from the successive stories, Fig 3. These dia- 
phragms are made of sheet iron, which is secured by methods effectu- 
ally preventing the leakage of air from the plenum into the exhaust 
conduits. Wherever practicable, the diaphragm is so placed as to 
remove the supply conduit from the outer walls, and to bring the dis- 
charge conduit against them. 

Because of the small space occupied by the entire system, veloci- 
ties of the air moved must be high. To secure to each register of the 
lower stories its proportion of air, and to prevent its going by such 
register under the momentum of its movement, deflectors are used, 
the area of each and the angle at which it is set controlling the air 
volume issuing from each register. Similar deflectors, set in a reverse 
position, are used for the outlets from the upper stories. To 
thoroughly break up and diffuse the swift flow of cool air in solid cur- 
rent from the register, dilf users, such as are shown in Fig. 1, are used 
with gratifying success. 

The building accommodates some three hundred students, and the 
air supply is nearly ^,000,000 cu. ft. per hour, the fan running at 
250 revolutions. The students are massed now here now there in 
class rooms, drawing rooms, and laboratories. Provision is made for a 
corresponding distribution or concentration of air supply, but the results 
without such alteration are so generally satisfactory that the valves are 
not used. Within the best filled rooms the largest proportions of 
carbonic acid thus far found are tc^^oo ^^ to^^oo' ^°^ ^^^ uniformity 
of the proportions in all parts of the rooms has been found exceptional. 

The warming is effected by three systems. Because of the large 
amount of steam work done in the basement, air must be supplied in 
large quantities, and at a temperature ranging from 45° to 55°, accord- 
ing to laboratory work and outside conditions of weather. The eight 
distributing flues cannot supply air to the several floors or rooms at 
different temperatures. They must supply it at the temperature 
required by that room above the basement most easily warmed to the 
point desired. Therefore, it becomes necessary to provide means for 
supplying air through one system of conduits to the basement at, say 



26 

50°, and to all rooms above the basement at 70°, and to further warm 
the air by direct means in such rooms as require supplementary heat. 

The air is heated before it reaches the fan to 50°, a " Standard " 
metallic thermometer mounted in the fan case indicating the tempera- 
ture, which is controlled by regulating the steam pressure in the coil. 
In moving under pressure through the sub-basement conduits the air 
leaks generously, as was anticipated, through innumerable small 
vents, the current being no where sensible, though the aggregate 
volume amounts to some 750,000 cu. "ft. per hour. Reaching the 
base of the flues, the air passes through steam coils so made and 
placed that the flue area is not obstructed. The control of steam to 
these coils is by means of the Johnson electric regulating apparatus, 
the thermostat being hung on a crane before the supply register on 
the third floor. Whatever the temperature in the sub-basement con- 
dCiits, the air supply to the rooms may be maintained at 70° or 72°, 
the range being confined within these limits by the automatic action 
of the reo^ulator. 

Within the rooms are placed wall steam pipes, the steam supply to 
which is regulated by the Johnson automatic apparatus, the thermostat 
being exposed within the rooms. For the quick warming of the 
building, the sub-basement conduit temperature may be run up to 100°, 
and the flue thermostat may be swung away from the register front. 
Air at such times may be rotated through the building instead of 
being taken from the outside. 

The performance of the apparatus for the automatic regulation of 
temperature has been satisfactory. The apparatus itself has required 
but little attention, and the general results in rooms warmed solely 
by steam surfaces having automatically controlled valves have more 
than justified the cost of its installation. 

The construction and arrangement of the auxiliary heater. Fig. 4, 
at the base of the flues is a matter of interest, because well suited to a 
successful working of the automatic method of steam supply. The 
steam enters at the top and through a valve so throttled that when the 
main conduit air is at its coldest the steam flow will be nearly con- 
tinuous. The coil drains through a check valve. Without such an 
arrangement the temperature within the flue would fluctuate through 
a considerable range, for on the wide opening of the supply and return 
valves steam would enter freely at both ends and suddenly heat up 



27 

the coil and the flue. It is desirable that the steam flow should be as 
nearly continuous as possible, and sufficient in quantity to warm the 
air passing through the coil. If the supply-valve is throttled, the drip- 
valve must be closed until the pressure within the coil is sufficient to 
force the accumulated water outward against the steam pressure. A 
throttled drip-valve would allow steam to back into the coil and cause 
pounding. But the check-valve holds back the steam and allows the 
condensation to collect until its weight and the steam pressure com- 
bined force the valve open and-the water out. The filling of the pipes 
with condensed water serves also the useful purpose of automatically 
regulating the length of their heated parts, and aids in maintaining 
the even temperature sought in the flues. 

The heating is for the most part done by the exhaust steam of 
engines and pumps used in the building, and to avoid the possibility 
of returning oily water to the boiler the condensation is passed into 
the sewer. For the purpose of cooling this water, and of utilizing its 
heat, it is passed through 800 feet of continuous 1:^" pipe, made into 
a trombone coil 38 pipes high, 7' long, and 3 pipes deep, placed before 
the inlet window. Fig. 2. In mild weather the condensation is so 
small that it goes to the sewer cold. When the outside temperature 
is low that of the chilled water is higher, the rate of condensation 
slightly exceeding that of the chilling. The maximum rate of flow in 
severe weather is about 1 cu. ft. per minute. 

The fan and combined heater, with directly attached engine, is of 
the Sturtevant pattern and make, with a large by-pass over the heater. 
The fan is 6' in diameter, and at 250 revolutions per minute supplies 
33,000 cu. ft. of air. Outside the inlet window a roaring sound of 
rushing air may be heard, due to the high volocities inflicted on the air 
in transit through the coil and fan because of want of space to give it 
larger passage and lower velocity. Within this sound is not heard, 
partly on account of the noise of moving machinery. 

The low pressure under which the heating system is worked and 
the irregular flow of condensed water, due in part to the intermittent 
supply of steam to the pipes, make the use of any ordinary steam trap 
impracticable. The method adopted for the relief of the New Build- 
ing system having given entire satisfaction, it has been adopted in this 
system also. It consists of a syphon trap made of a 4" pipe 18' long 
driven vertically into the ground, bushed at the top and tapped at the 



28 

side. Through the bushing runs a 2J" pipe to within 1' of the bottom of 
the large pipe. This pipe is bushed at the top, tapped at the side, 
and open at the bottom. The tap receives the water from the returns. 
The bushing receives a 1" pipe, which drains the supply main at a 
higher pressure than the return, and runs inside the 2^" to within 1' 
of the bottom of the large pipe. Within the trap there may, therefore, 
be two pressures and two heights of water columns on the steam side, 
one vent discharging the water of both. The only resistance or fric- 
tion is that due to the flow of water through the large pipes. 

All steam for the building is brought from the Rogers building 
through an underground 6" pipe, about 1000' long. The water con- 
densed in the heating apparatus is metered, and the record preserved 
for the purpose of record and investigation. 

The cost of the complete instalment was nearly as follows : — 

Fan, engine, main coil (1000 square feet), cooler, &c., . . * $1445 
4580 sq. ft. of direct steam surface, flue coils, mains, fittings, 

and placing, 4490 

Construction of ducts and sheet-iron work, 900 

Johnson's electric service, 1355 

Pump, Locke's regulators, sunken siphon-trap, covering 

mains, &c., . 775 

Total, $8,965 

The direct heating surface is as great as though the heating of 
the building depended solely upon it, as insufficient boiler power 
threatened to make the use of the ventilating system impracticable in 
severe weather. Furthermore, if air is passed into the rooms at the 
temperature at which it is desired to keep such rooms, to maintain 
that temperature, the direct surface must be as large as would be 
required for heating by direct radiation. 

The system is practically a dual one, the capacity of either part 
being enough for the heating of the building. The ventilating sys- 
tem includes the main heater, cooler, fan, engine, duct, supplement- 
ary heaters in flues, &c. Its cost may be put at $3500, and the bal- 
ance may be charged to the heating plant. The total heating surface 
is about 1 sq. ft. to 110 cu. ft. of space. 

* This sum includes a gift of $1000 made to the Institute by Mr. Sturtevant. 



29 



Handicapped by the conditions imposed, the work is of interest 
not so much as an illustration of a perfect system as of what may be 
accomplished under difficulties. 

The following table puts the arrangements for the ventilation of 
the New Building in contrast with those for the Engineering Build- 
intj : — 

?rew BuildiBg. Eng. Building. 

Area of inlet windows, 106 sq. ft. 33 sq. ft. 

Area through steam coil, 120 " 20 " 

Area of fan mouth, 65 " 13.3 " 

Area of fan discharge, 150 " 12.2 " 

Area of floor occupied by fan room and heat- 
ing chamber, 720 " 120 *' 

Area of main heating coil, 2200 " 1200 

Area of flues for supply and discharge of air, 240 " 96 " 

Number " " " " " " " 83 " 8 
Air volume supplied, cu. ft. per hour, . 3 600,000* 1,950,000 

Fan revolutions, 80 to 100 250 

* In mild weather tliis is increased to 6,600,000, — fan revolution 100, and indicated horse- 
power expended IT. The fan is now run by an independent engine, and not as heretofore 
at a fixed speed. 




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